On Tue, Mar 31, 2009 at 1:20 PM, Scott Marlowe <scott.marl...@gmail.com>wrote:
> On Tue, Mar 31, 2009 at 10:04 AM, Rafael Domiciano > <rafael.domici...@gmail.com> wrote: > > Hello People, > > > > I have some doubts about Vacuum Full. There We go: > > 1) The Only thing that Vacuum Full (Only Full, not Analyze) is to clean > > "dead space" on the disc, and reorganize the relation at the physical > level? > > If it's true, so doing this may speed up select's, while the Postgres > will > > going to do less hit in the disc. I'm right? > > Generally speaking, vacuum full should not normally be needed. > Regular vacuuming should free up enough free space that the table > reaches an equilibrium where it has some small percentage of available > space (5 to 15% or so) and stay there. So, why Vacuum Full should not nomally be needed? Vacuum Analyze is enough for Maintenance Base? One more question, If I understood Vacuum Full it's similar to Defrag Tool like Defrag Windows. So, like defraging Windows, it's speed up a little (the disc is going to read the blocks faster) , Vacuuming Full Postgres should have the same behavior?! > > > > 2) Doing only Vacuum Analyze I have a enlargement of the parameter > > max_fsm_pages. Does it have any impact in the operation? > > Should I increment the value in the conf to be so large than the Vacuum > > Verbose shows me? > > If the needed fsm settings need to keep increasing then something is wrong. The fsm_pages values incresead from 120000 to 320000, and now is around that every day. On more question, the postgres.conf max_fsm_pages is set to 150000, and every vacuum hint me to increase this parameter. Does it have any impact in the normal operation of Postgres? > > > > 3) There are differences in performace of Vacuum Full between versions > 8.1.4 > > and 8.3.7? > > As soon as possible we are going to migrate the Postgres to 8.3.7, just > > waiting the finish of the tests of the software in the new version. > > Yeah, 8.3 is faster. > > > 4) The right way to run Vacuum and Reindex is: Vacuum and Reindex or > Reindex > > and Vacuum? > > Running Vacuum I have a Index Bloat, right?! So I have to run Reindex > afet > > Vacuum?! > > If true I'll change the script to make first Vacuum and then Reindex. > > yep, vacuum full, then reindex. > > > 5) Does have any way to see how much is left to finish vacuum? > > Not that I know of. > > I notice you don't mention autovacuum. Are you running it? And if > not, why not? No, I'm not running autovacuum in the 8.1, but in the 8.3 I'm going to autovacuum by default. Thnks for Response